The invention relates to a work cylinder as defined hereinafter. A work cylinder of this kind is known (German Auslegeschrift 11 48 451). These work cylinders have the disadvantage that the position of the work piston that is movable in the work cylinder has to be known at all times. Suitable electric detection means, such as end switches or the like, are also already known.
Most recently, work cylinders of this type are also used in combination with electronic switch devices, and they are provided on vehicles in which they take on the task of final control elements of electrically controlled clutches of vehicle engines, as an example. In vehicles, there is always the problem that a breathing chamber located behind the work piston must be prevented, as it expands from the piston motion, from aspirating any dirt, or in the winter, air-borne salt. Such foreign substances could in fact cause corrosion and result in blockage of the work cylinder.
It has already been proposed that the breathing chamber be connected to the ambient air via a snorkel with a filter (German Offenlegungsschrift 24 30 394).
A thus-equipped work cylinder can then safely overcome any water damage, because access to the snorkel and its opening can be placed high enough that water will not be aspirated into the breathing chamber when the vehicle goes through water.
The disadvantage here is that special means always need to be provided to assure dirt-free breathing of the breathing chamber. Another disadvantage of the first work cylinder named above is that installation of the sensor takes up space.